Multiple Rails

This is interesting about rails and I had a lengthy discussion with my friend at the Cheesecake Factory today but I had to cut it short because he was having wife and in-law problems - wanted my input on that. :roll:

Multiple rails in a power supply has nothing to do with the power supply efficiency or its ability to provide clean and stable power. The rails in a power supply refers to the way current protection is configured. A multi rail power supply has multiple current protection circuits, each one monitoring a different set of cables leaving the power supply. So, lets say a power supply is pushed beyond its capabilities or a short circuit occurs, the power supply will shut down to prevent further damage to the PC components.

A single rail will usually just have over current protection as a means of shutting down your power supply in a event of a short.

Example, lets take Stiltz85 rig and lets say for some reason his mobo needs more power and a surge is happening, with a multiple rails power supply - one of the power protections or more will kick in and stop the surge of power being sent to the mobo and the power supply will shut down or power off. Sometimes, the damage is done to one of the components but not all of them. Now if Stiltz85 had just a single rail and the same problem as above took place, then hopefully his over current protection will signal his power supply to shut down, but what if that fail? Damage mobo, ram or even a fire could have started. Which he can kiss off his investment.

When your looking at power supplys spec's, you should be looking for Over curent protection (OCP), Over voltage protection (OVP), Short circuit protection (SCP), Over power protection (OPP) and Over temperature protection (OTP), along with everything else in a power supply.

I take it back about the Corsair AX1200 being that its only a single rail and you have a lot of things going on in your PC. Twelve hundred watts is still ample power for the 3-way SLI, but if it only had multiple rails.

In a nut shell...I think I remember everything then maybe not too,
Alpine79
:alien:

I kind of honestly prefer a small amount of rails compared to (for example) an 4+ rail PSU. You can have issues with Rail voltage balancing and with some PSU's, especially the ones with a lot of rails, the Amp rating can actually be lower then what you need.
Say you have a few B.A. graphics cards that you want to overclock, so you do it and say you have an 8 rail PSU, well that is pretty much 1 rail per GPU. You go to boost the juice and you overload that circuit because the rail can not supply the amps for the job. The PSU kicks into OMG mode and shuts down and you are now possibly out one nice graphics card.
I just like the thought of having two or three really beefy high ampere rails so I know my PSU can keep up. Many of the few 1500W PSU's I have looked at have a lot of rails and it actually kind of discourages me to have all of that "protection".
Although I could be wrong, I do not know for sure if that is the way PSU Volt rails work, I have just ran into issues like that with other things and I have not read up too much on the ampere ratings of multiple 12V rails.

Come to think of it, if the rails on a PSU work the way I think they do, I might just be happier with the one rail. Multiple rails could have issues with trapped capacity and such.. I have to do some google homework. :-?

Edit: okay, did some looking around and I think the Thermaltake Toughpower XT 1475W Gold is around what I want, two 12v rails and one of the rails is rated at 75A/900W, sounds like all three of my graphics cards can be added to the one rail. while the other 12v rail is rated at 55A/660W and can pretty much power everything else with ease, meanwhile the 3.3v and 5v are rated for 25A each and 150W. Yes boys and girls, this 1475W (Rated for sales in America) is actually capable of over 1,700W! Daddy likey! :twisted:

Does anyone think I will have the juice to add a pump and enough fans to do a push/pull on two radiators?

You might be cutting it close man, I went to thermaltakes power calculator, and entered your info in, I don't know what else you have so i went with 2 hd at 7200fpm, 1x cd drive,1xdvd drive. This is with no OC on that cpu also. it's 919watts, again not including other usb devices and what not. If you oc your cpu and gpus your cutting it REALLY close.

Re: Corsair AX1200 PSU: Can it cut it?

Originally Posted by Tperk

You might be cutting it close man, I went to thermaltakes power calculator, and entered your info in, I don't know what else you have so i went with 2 hd at 7200fpm, 1x cd drive,1xdvd drive. This is with no OC on that cpu also. it's 919watts, again not including other usb devices and what not. If you oc your cpu and gpus your cutting it REALLY close.

Really? That's excellent news! I'm just running one solid state drive at the moment, and only one optical drive (blu-ray multi drive), not much for USB use besides my external 2TB HDD(has it's own power sorce), keyboard, mouse, Razer Nostromo, and a wired XBOX 360 controller.
I will admit, I am overclocking my CPU a little at the moment but I honestly don't need to with what tasks I have given this beast already. And I know the AX850 actually makes over 1000W so I think it would be safe to assume the AX1200 makes up to 1400W, maybe more. I might be in the clear here, I've read a lot from other AX1200 owners that this power supple is a beast and pretty much takes on everything you can throw at it, I just wish I knew someone with a setup like mine on this PSU just so I could get reassured.